Apparatus for anchoring tubing strings in well bore conduits



March 19, 1957 R. c. BAKER 2,785,758

APPARATUS FOR ANCHORING TUBING STRINGS IN WELL BORE CONDUITS- FiledApril 2, 1954 2 Sheets-Sheet 1 C j?? 1. C

ATTORNEYS.

' March 19, 1957 R. C. BAKER APPARATUS FOR ANCHORING TUBING STRINGS INWELL BORE CONDUITS Filed April 2, 1954 j if, 25

2 Sheets-Sheet 2 HIM! 4f mmm- 45 INVENTR.

www

TTOQNEYS,

iinited States APPARATUS FOR AN CHGRING TUBlNG STRINGS EN WELL BRE.CONDUIT S Reuben C. Baker, Coalinga, Calif., assgnor to Baker Gil Tools,Inc., Los Angeles, Calif., a corporation of California Application April2, 1954, Serial No. 420,527

Claims. (Cl. 166-212) proved subsurface well tool capable of anchoring astring of tubing in a well casing against longitudinal displacement, thetool being capable of safely withstanding comparatively high pressures.

Another object of the invention is to provide a hydraulically actuatabletubing anchor operable by pressure diderentials internally of the toolto move and hold the anchoring members against the well casing, in whichthe tubing anchor embodies devices for equalizing internal and externalpressures, if necessary, in order to obtain reiease or" the tool fromthe well casing, in the event such pressures are not otherwiseequalized.

A further object of the invention is to provide a tubing anchor havinggripping members that are expanded outwardly into engagement with a wellcasing by hydraulic pressure within the tool, in which any pressuresbelow the tool and tending to elevate it are utilized to engage thegripping members more securely against the well casing.

Yet a further object of the invention vis to provide a tubing anchorhaving gripping members expanded outwardly into engagement with a wellcasing by hydraulic pressure within the tool, in which release of thegripping members can be assisted by imposing a downward force on thetool in the well casing.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration'of a formin which it may be embodied. This form is shown in the drawingsaccompanying and forming part of the present specification. lt will nowbe described in detail, for the purpose of illustrating the generalprinciples of the invention; but it is to be understood that suchdetailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure l is a combined longitudinal sectional and side elevational viewof an embodiment of the invention, with its gripping members inretracted position, to enable the tool to be moved longitudinally in awell casing;

Fig. 2 is a view similar to Fig. 1, disclosing the equalizer valve inopen position;

Fig. 3 is a view similar to Fig. 1, disclosing the tubing anchoranchored against the well casing;

Eig. 4 is a fragmentary enlarged longitudinal section or" a portion ofthe equalizer valve.

As disclosed in the drawings, a -tubing anchor A is to be loweredthrough a string of well casing B by means ot` a string of tubing ordrill pipe C to a point in the casing at which it is to be anchoredtherewithin. The tubing anchor may be connected with another tool (notshown) secured to its lower end.A As an example, this undisarent icegage the well casing in packed-oir condition and resist downwardmovement therewithin.

The tubing anchor A includes an upper tubular mandrelor inner member 11iadapted to be threadedly attached to the lower end of the tubing stringC. This tubular mandrel is telescopically arranged within a tubular body11 formed of several sections. Thus, the main intermediate portion 12 ofthe tubular body has its lower end threaded onto a lower body member 13,which may have a lower threaded box 14 for attachment to tubing or atool (not shown) therebelow. The upper portion of `the body 12 isthreaded onto a cap or lock ring 15 slidably engageable with theexterior of the tubular mandrel 16. To prevent foreign matter frompassing between the body 11 and mandrel 1li, a suitable rubber wiperring 16 may be secured to the cap 15 for slidable sealing engagementwith the mandrel 10.

Disposed around the body 11 in circumferentially spaced relation are aplurality of longitudinal slots 17 in which gripping members 18 areslidable. The sides of the gripping members slidably engage the sides ofthe;

slots 17, the gripping members encompassing a rubber, or rubber-like,expansion sleeve 19, whose upper and lower ends engage the interior ofthe intermediate body member 12 on opposite sides of the slots. Thelower portion oi the expansion sleeve 19 is disposed within an annularspace between the upper portion 20 of the lower body member 13 and theintermediate body member 12 below the slots 17. The upper end of therubber sleeve 19 is disposed within a companion annular space formedbetween the intermediate body member 12 and an outwardly directed ilangeportion 21 of an inner protective nipple 22, which depends from theilange portion along the inner surface of the rubber sleeve 19, andwhose lower end engages a shoulder 23 on the lower body member 13. Thisnipple or protective member 22 has a plurality of side ports 24establishing communication between the interior of the nipple 22 and theinterior of the rubber expanding sleeve 19. The inner nipple 22 is heldin a downward position in snug engagement with the shoulder 23 by aclamp nut 25 threaded into a threaded box portion 4b in the upper end ofthe intermediate body member 12 and engaging the upper end of thenipple. This nut 25 is prevented from loosening by a suitable set orlock screw 26 threaded through the body wall and engaging the clamp nut.

closed tool may consist of a well packer adapted to en- Leakage of fluidaround the upper end 19a of the expansion sleeve is prevented by formingit as a lip or edge adapted to engage the inner wall of the intermediatebody member 12. Similarly, leakage of Huid around the lower end 19h ofthe expansion sleeve is prevented by forming it as a lower lip sealengaging the inner wall of the intermediate body member 12. Fluid underpressure between the expansion sleeve 19 and the nipple 22 will pressthese upper and lower lip seals 19a, 1% securely against the inner wallof the intermediate body member 12', and prevent such uid from passingaround the sleeve to its exterior. Leakage of uid endwise from theexpansion sleeve 19 is further prevented by a suitable upper side sealring 27, such as an O ring made of rubber or rubberlike material,contained within a groove 28 in the upper portion of the nipple andengaging the inner wall of the intermediate body member 12. Similarly,leakage of iiuid through the threaded joint between the intermediatebody member 12 and lower body member 13 is prevented by a rubber orrubber-like O ring 29, or corresponding side seal, contained within agroove 315 in the lower body member 13 and engaging the inner wall orthe intermediate body member 12 below the lower lip 19b.v It is evidentthat the lip seals 19a, 19]) and the side seals 27, 29 prevent fluidfrompassing out of the interior of the'rubber expansion sleeve 19 exceptthrough the nippleV ports 24.

Fluid under pressure within' the tubular mandrel 10 and the nipple 22exerts an outward expanding force on the rubber expansion sleeve 19,carrying the gripping members 18. outwardly toembed their externalportions 18u; which may be provided 'with suitable wickers or teeth,outwardly into anchoring4 lengagement withV the wall of the well casingBf When theA internal pressure is relieved or' substantially equalizedwith respect to the external pressure, the gripping members are releasedand may be fully retracted by means of upper and lower springs 31contained within upper and lower sockets 32 provided in the upper andlower terminal portionsi33, 34 of each gripping memberyand bearingvagainst upper and lower stop or retainer rings 35 secured to the'exterior of the intermediate body memberlZ on opposite sides of thelongitudinal slots 17 Vintany suitable manner, as through use ofA theupper and l'wer screws 36. Thus, it is apparent that the helicalcompression springs 31 are constantly urging the gripping members 18 toa retracted position out of engagement from the wall of the Well casing,to correspondingly shift the rubber expansion sleeve 19 inwardly.However, this sleeve inherently tends to assume the `inward positionshown in Figs. l and 2. When a pressure diierential of a suicientmagnitude to overcome the inherent elasticity of the rubber sleeve 19and the force of the springs 31 is imposed within the tool, then therubber sleeve 19 is expanded outwardly to correspondingly expandthegripping members 18 outwardly into anchoring engagement with the 'casingB. VThe higher the pressure dierential within the tool, the greater willbe the force holding the gripping members anchoredto the Well casing. Y

As described above, the grippingrmembers 18 are released upon therelieving of the pressurel internally of the tubing string C and tool A,or its substantially equalizing with respect to therexternal pressure.In the event that a. mere relievingrof the pressure internally of thetool cannot occur, then an egualizing valve 37 is `embodied in thetubing anchor A, to make it possible Yfor such pressurestribe-substantially equalized. s

A'Jhe tubular mandrel o r inner member 10 has an outwardly directedflange 3Sv provided with externalleft-'hand threads 39 meshing withcompanion internal left-hand threads 40 in the intermediate body member12. The internal left-handrthreads 40 may be the same .set of threads asare threadedly engaged by the clamp nut `25 and the upper cap or lockring 15. The mandrel flange 38 is of a much shorter length than thedistance :between the upper end of the clamp nut 25 and the .lower .endof the cap 15, permittingthe mandrel 10gto move longitudinally in bothdirections upon its rotation within the body 11 to the extent ylimitedby engagement of the upper angeshoulder 41 with the .lower end of thecap YI5, for of the lower ange shoulder 42 with the'upperend kof theclampnut 25.

yWhen the mandrel 10 is threaded downwardly of the bodyll and occupiesthe position shown inFigs. 1 and 3, its lower cylindrical valve headvportion `43 is moved Within-a. cylindrical seat 46in the clamp nut 25and nipple 22 into Vsealing engagement with a suitable seal Vring 47contained within a groove 43 formed collectively in the upper end of thenipple 22 and thelower/end ofthe'clamp nut 25. This Yseal 47 willsealingly engage theperiphery ofthe valve head and preventiluidfrom'passing around 'the exterior'of the'latter in "bothdirections. It.' is molded ohja-'metallic Vring 6G and has upper andlower outer lip portions 61 engagingthe 'base 48a of the grooveiS toprevent fluid leakage around the seal ringl "47 in vboth directions.When the mandrel is inthe lower vposition Vdisclosed in Fig. l, with thevalve head 45 engagingthe Yseal 47,l'luid cannot pass between theinterior and exterior of the tool througholne or more side'openings -orparts-49 .provided inthe intermediate bodyl member 12 above-the`clampnut 25. However, upon 'rotating the Vtubular-imanto they body, thetubular mandrel iselevated, by virtue of the threaded connection 39, 49,to the extent limited by engagement of the upper angeshoulder i1 withthe cap 15, which displaces the cylindrical valve head 45 above itscompanion seal 47, as disclosed in Fig. 2, which then opens the sideports 49 and allows the rluid to pass through these ports to equalizethe pressure internally and externally of the tubing anchor.

It is to be noted that the lower ends 50 of the slots 17 are inclined tosome extent' ina downward and outward direction to engage companioninclinedV surfaces 51 on the lower ends of the gripping members 1S. Theupper ends 52 of the slotsv 17 are also inclined in an outward anddownward direction, to engage correspondingly inclined surfacesr on theupper ends of the gripping members. The inclined surfaces 50, 51 at thelower ends of the slots 17 and gripping members 18 are utilized toassist in holding the gripping members in their outward anchoredposition against the well casing B, whereas the upper surfaces 52, 53are of'a retracting character, to facilitate release and retraction ofthe gripping members 18 with respect to the well casing B.

ln the event the gripping members 1S have been expan-dedV outwardly bythe expansion sleeve 19 and an internal pressure differential ismaintained within the tool, then the hydraulic forces may be acting onthe body member 11 from below, or on some other equipment (not shown)Ysecured to the body and tending to elevate the latter. Should thisaction tend to occur, then the lower expander surfaces 50 are broughtupwardly into engagement with the companion surfaces 51 at the lower endof the gripping members 18 and exert a laterally outward component oforce't'ending to hold the gripping members 18 yanchored against the wellcasing B.

Conversely, should the pressure within the tool be released, orequalized with respect to the pressure externally of the tool, and thegripping members 18'stil1 fail to retract, then a downward force can beimposed on the tubing I'string C andi'nandiel 1.0, which will b e'transmitted through `the intermediate 'body member 12 and. cause theupperretracting surfaces V52 to engage the companion surfaces Y 51% onthe upper ends of the gripping members -18 to urge the 'latter in .aninward direction.

Normally, theplarts of @the tool `.occupy the relative positions shownin Fig. l, in which theequaliziug valvef37 is closed and thegrippingmembers 18 and expansion sleeve 19 Yare retracted. 'The tool A, usuallyconnected to another ltool .or well 'packer therebelow, is lowered inthe well casing -B `tothe point at which it is to be anchored to theWell casing. The lluid in lthe Vtubing string C and within the toolA maythen Vbe subjected to pressure, the tool therebelow (not shown) usuallyeffecting a seal with the well casing enabling a .pressure t0 be builtup within the tubing string C and the tubing anchor A. This uid underpressure will pass through the nipple ports 24 and expand the expansionsleeve .19 outwardly, Vforcing theanchoring members 18 laterally outwardin their slots 1-7 intoY anchoring engagement with the Wall ofthe wellcasing B (Fig. 3). -As the pressure diierential increases, the greaterVis the anchoring force exerted in an outward .direction uponthe'ianchon'ng members 18. The wickers or teeth 18a on thefanchoringmembers are designed to resistlongitudinal.displacementofetool A in both an upward and -a downward-:direction Whenever.itl-isdesired :ton'elease the .tubing anchor A, it is merely necessarytoerelievethepressure therewithin, which will allow --the expansion.-Sleeve 19 to retract inherently, andY whichfwill enableithe retractorspring 31 to'shift Athe'grippingzmembers 18 back Yto their retractedpositions, such 'asshown in Fig. ,1, which will then allow the :tubingstring C. and the :tool 'A ato .be `VVmoved longitudnallyin .theme11casing-fin either'anupward orzdownwardfdirection. VWith thefpartsinithecondition just ref erred to, the tool A can be elevated in thewell casing B and removedcompletely from the well bore.

dhould a pressure differential remain in the tubing string C and thetool A, the gripping members 1S will be held in their anchored positionagainst the well casing, in the manner disclosed in Fig. 3. Under theseconditions, the gripping members i8 will prevent rotation of the body 11of the tool, w ereupon the tubing string C and the tubular mandrel 10may be rotated in a clockwise or right-hand direction, to thread themandrel upwardly within the body 11 and lift the valve head 45 above itscompanion seal 47, such as shown in Fig. 2, opening the side ports 49and allowing the pressure internally and externally of the tool toequalize, thereby eilecting retraction of the packing sleeve 19 and thegripping members 18 from the well casing. The tubing anchor A may now beelevated or lowered in the well casing B.

In the event it is desired to again expand the gripping members 1S intoanchoring engagement with the well casing, the mandrel 10 must berelowered, to place its valve head 45 in sealing engagement with thecompanion seal 47` Such relowering action will occur by suitably holdingthe body ,ll against rotation to permit the tubing string C and mandrel10 to be rotated in a couuterclockwise direction, or to the left.Usually, the tool (not shown). connected to and disposed below thetubing anchor A has provisions for preventing its rotation, which willalso forestall rotation of the body 11 of the tubing anchor, to which itis connected. Following the relowering of the mandrel l@ and closing ofthe side ports 49, a pressure differentim can again be imparted to theuid in the tubing string C and tool A to again expand the anchoringmembers i8 outwardly into rm gripping engagement with the wall of thewell casing B.

The inventor claims:

l. In an apparatus to be anchored in a Well casing disposed in a wellbore: a body having circumferentially spaced slots therein; casinggripping members slidable laterally in said slots; a pliant, elasticsleeve within said body and gripping members sealingly engaging saidbody on opposite sides of said slots and expandible outwardly by uidunder pressure therewithin to shift said gripping members outwardly intoengagement with the well casing; and a sleeve within said elastic sleevexedly and immovably secured to said body 'and having a port fordirecting uid under pressure into the interior of said elastic sleeve,said sleeve secured to said body having means thereon engaging saidelastic sleeve to prevent an end portion of said elastic sleeve frommoving yaway from sealing engagement with said body.

2. 1n an apparatus to be anchored in a well casing disposed in a wellbore: a body having circumferentially spaced slots therein; casinggripping members shdable laterally in said slots; a pliant, elasticsleeve within said body and gripping members sealingly engaging saidbody on opposite sides of said slots and expandible outwardly by uidunder pressure therewithin to shift said gripping members outwardly intoengagement with the well casing, the lower ends of said slots and thelower ends of said gripping members being inclined in a downward andoutward direction and engageable with each other upon upward movement ofsaid body relative to said gripping members to urge the latter laterallyoutward.

3. In an apparatus to be 'anchored in a well casing disposed in a wellbore: a body having circumferentially spaced slots therein; casinggripping members slidable laterally in said slots; a pliant, elasticsleeve within said body `and gripping members sealingly engaging saidbody on opposite sides of said slots and expandible outwardly by tluidunder pressure therewithin to shift said gripping members outv ardlyinto engagement with the well casing, the lower ends of said slots andthe lower ends of said gripping members being inclined in a Vdownwardand outward direction and engageable with each other upon upwardmovement of said body relative to said gripping sleeve within saidelastic sleeve secured to said body and having a port for directingfluid under pressure into the interior of said elastic sleeve.

4. ln an apparatus to be anchored in a well casing disposed in a wellbore: a body having circumferentially spaced slots therein; casinggripping members slidable laterally in said slots; a pliant, elasticsleeve within said body and gripping members sealingly engaging saidbody on opposite sides of said slots and expandible outwardly by iluidunder pressure therewithin to shift said gripping members outwardly intoengagement with the well casing, the lower ends of said slots and thelower ends of said gripping members being inclined in a downward andoutward direction and engageable with each other upon upward movement ofsaid body relative to said gripping members to urge the latter laterallyoutward; the upper ends of said slots and the upper ends of saidgripping members being inclined in a downward and outward direction andengageable with each other upon downward movement of said body relativeto said gripping members to urge the latter laterally inward.

5 ln an apparatus to be anchored in ya well casing disposed in a wellbore: a body having circumferentially spaced slots therein; casinggripping members slidable laterally in said slots; a pliant, elasticsleeve within said body and gripping members sealingly engaging saidbody on opposite sides of said slots and expandible outwardly by fluidunder pressure therewithin to shift said gripping members outwardly intoengagement with the well casing; the upper ends oi said slots and theupper ends of said gripping members being inclined in a downward andoutward direction and engageable with each other upon downward movementof said body relative to said gripping members to urge the latterlaterally inward.

6. in apparatus to be anchored in a well casing disposed in a well bore:a body having circumferentially spaced slots therein; casing grippingmembers slidable laterally in said slots; a pliant, elastic sleevewithin said body and gripping members sealingly engaging said body onopposite sides of said slots and expandible outwardly by fluid underpressure therewithin to shift said gripping members outwardly intoengagement with the well casing; a tubular mandrel connectible to atubing string and telescoped within said body vand movablelongitudinally relative thereto, said body having a side port above saidelastic sleeve; and valve means operable by said mandrel in response tomanipulation of the tubing string and moving longitudinally of said bodyto selectively open or close said body side port.

7. In an apparatus to be anchored in a Well casing disposed in a wellbore: a body having circumierentially spaced slots thereing. casinggripping members slidable laterally in said slots; a pliant, elasticsleeve within said body and gripping members sealingly engaging saidbody on opposite sides of said slots and expandible outwardly by iluidunder pressure therewithin to shift said gripping members outwardly intoengagement with the well casing; a tubular mandrel connectible to atubing string and threaded within said body for movement longitudinallyrelative thereto; said body having a side port above said elasticsleeve; and valve means operable by said mandrel in response to rotationand longitudinal movement of said mandrel with respect to said body forselectively opening or closing said body side port.

8. ln an apparatus to be anchored in a well casing disposed in a wellbore: a body having circumferentially spaced slots therein; casinggripping members slidable laterally in said slots; a pliant, elasticsleeve within said body and gripping members sealingly engaging saidbody on opposite sides of said slots and expandible outwardly by iluidunder pressure therewithin to shift said gripping members outwardly intoengagement with the well casing; a tubular mandrel connectible to atubing string and threaded within said body for movement longitudinallyrelative, theres; Sad. bedr having a Sid@ am; valve means: @perale bySad mandrel' in responser 10. ,rQfafQtl and Qgsitudivral @vement 0fSaid, mandrel Withfespegt to s'aidbody for selectively opening orclosing said body sidepert; and a sleeve within said elastic sleevesecured to said body and having a port for directing fluid underpressnre into theA interior of said elastic sleeve.

9, In an apparatus'to be anchored in a Well casing disposed in a Wellbore: a body having circumferentially spaCCd Slots therein; casinggripping members slidable laterally insaid slots; a pliant, elasticsleeve Within said body and gripping members sealingly engaging saidbody on opposite sidesY of said slots and expandible outwardly by fluidunder pressure therewithin to shift said gripping members Qlltwardlyinto engagement with the well casing; a tubular. mandrel connectible toa tubing string and threaded within said body for movementlongitudinally relative thereto; said body having a side port;valverneans operable by said mandrel in response to rotation andlongitudinal movement of said mandrel with respect to said body forselectively opening or closing saidvbody side port; the lower ends ofsaid slots and the lewer ends of said gripping members being inclined ina downwarl and outward direction and engageable with each other uponupward movement of said body relative to said gripping members to urgethe latter laterally outward; and a sleeve within said elastic sleevecasing; a sleeve Within said elastic sleeve irredly and movably securedto said body and'having a poi-ttor recting uid under pressure into theinterior of said elastie sleeve; a tubular mandrel connectible to atubing .s t g and. telescope@- wfhia 'Sad batir and. mprablezsl wdinally relative thereto; said body having a side port; and valve meansoperableby said mandrel and rfrioya longitudinally of said body'toselectively open Yar'iclfcese said body side port.

References. Cited the 519 Qf, this parent UNTED- STA-fili??v PATENTS,

2,352,700 Ferris July 4, 1944 V.7.,3,7(),8-3` 2 Baker. Mar. 6,Y 19.452,584,448 Hern Feb. 5, 1952 2,603,163 Nixon Iuly- 15', 1.952 2,638,168Parks Mayl 12,1953

